A concentrator comprises an upward port used for being coupled to host equipment which supports a first data format and/or a second data format, a plurality of downward ports respectively used for being coupled with slave equipment which supports the first data format and/or the second data format, a sub concentrator used for supporting the data transmission of the first data format between the plurality of downward ports and the upward port, a second sub concentrator used for supporting the data transmission of the second data format between the plurality of downward ports and the upward port, a data format detector used for detecting the data format supported by the host equipment and the slave equipment which are mutually coupled, a transaction translator coupled between the first sub concentrator and the second sub concentrator, coupled to at least one downward port, and used for performing conversion between the first data format data and the second data format data, and a controller used for controlling the first sub concentrator, the second sub concentrator and the transaction translator, and used for deciding whether the conversion is performed or not according to the detected data format.